Simon Cowell has admitted he "felt like a bit of an idiot" after learning Britain's Got Talent winner Jules O'Dwyer used a stunt double dog during the final.

The disclosure that a lookalike dog was used to walk the parallel ropes sparked 507 complaints by yesterday evening to communications watchdog Ofcom and another 130 to ITV.

ITV boss Peter Fincham said the presentation of the act was a "judgment call" and the use of another dog, Chase, should have been made clearer.

And now Cowell revealed the "c*ck up" had left some producers in tears.

He told the Daily Mirror: "The moment I found out I literally put my head in my hands. I spoke to a lot of people after, and I did raise my voice. But it was mainly people owning up to it. They felt embarrassed, they felt frustrated, they felt stupid but you've got to man up to this stuff.

"The producers are absolutely gutted. I was so depressed for the show, for Jules and for the producers themselves, because they are not horrible people. They didn't think how it would appear. I was frustrated because I didn't really know what I was judging until afterwards so I felt like a bit of an idiot."

Cowell added he welcomed an Ofcom probe, saying no-one had sought to hide Chase's appearance, but he felt the show had let O'Dwyer down.

"There's a cloud over her and I want that cloud to go. I want people to feel proud of her and that she did well and she should be happy," he told the paper.

Yesterday, guide dog trainer O'Dwyer, who beat Welsh choir Cor Glanaethwy and magician Jamie Raven to the £250,000 prize with a sketch involving a tightrope and stolen sausages, said she did not use Matisse, the dog which viewers believed performed the stunt, because he did not like heights.

"I was disappointed when people said I allegedly hid Chase and I was trying to make it like Chase was Matisse. That's not so," she said.

"I introduced Chase in the semi-final, and I said Chase is Matisse's best mate. Why put the pressure on the dog when I already have another dog who can perform it on television?"

There was no sign of Chase when O'Dwyer and Matisse heard from the judges and spoke to hosts Ant and Dec immediately after her performance, and Cowell admitted "that should have happened".

Some outraged viewers expressed their anger on Twitter, claiming to have been "misled" over the tightrope stunt.

An Ofcom spokesman said that complaints will be assessed before a decision is taken on whether to investigate.